Construction of road pavements and other surfaces



July 17,` 1934. l.. R. H. sRvlNE 1,966,750

CONSTRUCTION OF ROAD PAVEMENTS AND OTHER SURFACES Filed April 17, 1929 IN VEN TOR.' L. E. 71. frz/227e ATTORNEYS.

Patented `July 17, 1.934

UNITED STATES Lionel Robert Herborn lirvine,` Killara,NeW South Wales,

Australia Application April 17, 1929, Serial No. 355,987 In Australia May 7, 1928 1 Claim.

This invention relates to the construction of pavements for roadways, fcotways and other prepared surfaces such as tennis courts or the like and the object of the invention is to provide a simple and inexpensive process for the economical construction of smooth and durable surfaces for the above purposes by the utilization of earth, clay or other similar material occurring naturally at or near the site of the pavement.

The invention has been more especially devised for the construction of durable road pavements at low cost in localities where natural stone does not exist or where the expense involved in blasting, quarrying, crushing and transporting the stone is greater than the cost of treating the natural earth material in place upon the road by the process described herein.

In the accompanying drawing is illustrated a road surface constructed in accordance with this process, and Figure l shows a plan view of such surface while Fig. 2 shows a vertical section thereof.

The invention consists essentially in preparing the area to be constructed until an even surface of the required shape is obtained, such surface being then divided into a number of sections 10 by cutting or by any other suitable means and then dried and heated to hardness by a moving furnace or other heating apparatus. The spaces 11 between the sections are then lled with any suitable and well known binding material.

The invention may be more clearly understood from the following description of the process carried out in the construction of a pavement according to the invention.

The area to be treated if of earth, shale, clay or other material suitable for this process, is drained, formed and consolidated and otherwise prepared by means of suitable plant until the surface is smooth and of the required shape.

During such preparation the material is watered to produce a closer bond and Contact between the particles thereof, while if a higher class of finished pavement is required the material may be pugged or puddled and plastered to an even surface. The consolidation may be effected in conjunction with the watering by any suitable means such as rolling with a roller of suitable weight.

If the area is not naturally composed of suitable material the surface of the pavement on the site of the work may be built by applying material of suitable characteristics and, treating it as described above.

The consolidated and even surface is then divided into sections or pieces of any desired shape 1";

and size in any suitable and well known manner by the formation of systems of cracks l2, see Fig. l.

The material is then heated to hardness, while in its iinal position, by a furnace or heating apparatus of suitable design arranged to pass progressively over it until the surface acquires an appearance and hardness comparable with that of concrete or bricks. The depth to which the hardening effect is required to extend will depend upon the traiiic to be carried and will be determined mainly by the period during which the heat is applied, the physical properties of the material andthe extent to which the division of the surface is carried out. The time during which the heat is to be applied will also depend upon these factors.

It has been found by experiment that the materials most suitable for the process are clay, decomposed shale, earth and loam having a high alumina content and that the hardening effect described above may be obtained with most like natural earths or soils.

The means for applying the heat to the surface may be of any well known type, but preferably will consist of a device acting generally on the principle of a reverberatory furnace in that the flames or products of combustion are directed by suitable shields and like apparatus on to the surface to be heated. Any well known fuel such as producer gas, oil and the like may be utilized and any well known arrangements for preheating the fuel or the surface to be treated and for eifecting economy in fuel consumption may be applied.

rhe temperature to which the surface is to be heated is sufficient to partially fuse or vitrify the material and will depend on the nature of the material and the degree of hardness desired. When clay is being treated the temperature necessary to bring it to the desired state is approximately 1800 degrees Fahrenheit.

The divisions or cracks which have been formed and those which may appear during the process of drying or heating may be lled with any well known and suitable binding material, such as bitumen, tar, cement,`sand, earth or clay, or a combination of these or like materials.

Essentially the result of the process is to produce a pavement which consists of sections 10 together in such a manner that the intervening spaces are in the formiof interstices or cracks 12, 13, 14 each having approximately parallel sides in place of the regular voids which exist in ordior pieces of hardened material tted and keyed nary roads and pavements made of broken stone. The process is characterized by this result, irrespective of whether such intervening spaces may have been formed mechanically prior to drying and heating or automatically by other causes such as contraction in the latter stages of the process. When the surface has once been formed in the soft state it is not again disturbed by scarifying or ploughing or similar operation.

A process for the construction of road pavements comprising keyed sections having approximately parallel sides in which process natural earth material selected from a group consisting of shale, clay and their equivalents is rst drained upon the site of the pavement, then shaped and watered while consolidated by rolling with suitable Weight, pugged, puddled and trimmed to an even surface of the desired shape, said surface being then divided into substantially parallel sided and keyed. sections of mutually corre- 'sponding shape, then dried and progressively 

